Conventional construction of tuning pins and similar instruments involves a threaded metal pin driven into a hardwood pinblock. The grip of the pin in the wooden block depends on the thread. The stress that has to be withstood by the wood often results in cracking, splitting or sagging of the pinblock. Moreover, wooden pinblocks are subject to changes in humidity and other climatic variables.
Once a pinblock cracks, sags, splits, shrinks or warps, the piano is in most cases too costly to repair or to salvage as the repair work is extremely labour-intensive. The most common major defect in old pianos is that they are unable to hold their tune as a result of the pinblock sagging, splitting or cracking.
In some instances, modern manufacturing techniques incorporate the use of laminated pinblocks and tuning pins of a larger diameter. This is done in an attempt to minimise effects of climatic changes and to improve tuning stability. However, these can act to make subsequent tuning more difficult.
Conventional wooden pinblocks are made from a selection of hardwoods which, from the point of view of conservation, is a diminishing resource.
In other constructions where a metal plate is used, the pins often break due to seizure in the plate especially if the time between tunings is long. The pins can also bend about the stress point when being tuned and set for example, of the Beale and Vader type as described in the Australian patent application 8777/07 filed the 22nd May 1907.
Therefore, in such constructions, the ability to be able to set the pin, when required, is impeded by its design.
Hence, an alternative construction is required.